Fortran version

Since Julia does not allow compilation to binaries yet, some researchers might find it hard to couple FastIsostasy.jl to their favourite ice-sheet model. To tackle this, a Fortran version has been developed. It however lacks some features, which are summarised below:

• Library of time-integration methods reduced to explicit Euler,
• Only fixed time stepping allowed,
• No inversion routines for the UKI,
• Computation on GPU not supported.

These discrepancies are unlikely to be gapped in the future, mostly because the Fortran ecosystem is less extensive than the Julia one.